Traffic barricades are commonly used to warn vehicle traffic and pedestrians of danger, and block off restricted areas. Barricades made of molded plastic have been known for some time. Examples are found in the Stehle, et al. U.S. Pat. Nos. 3,880,406 and 3,950,873 and the Glass U.S. Pat. No. 4,298,186. Barricades illustrated in these patents include, among others, barricades made with two panel units hinged together so that they can be spread apart for use and collapsed for storage or transport. The individual panel units are one piece, integral, hollow plastic panels, formed by rotational or blow molding. The lower hollow sections may contain ballast.
These early plastic traffic barricades were a great improvement over conventional steel and wood barricades. They are rugged, yet cause less damage to vehicles if inadvertently struck. Through the use of ballast in the units, the center of gravity of the barricade is lower than either wood or metal barricades. The result is a barricade less susceptible to being blown over by wind. Other features typically incorporated in such barricades are bright colored reflective horizontal panels, flashing lights or signs, and a structural member near the bottom where a sand bag can be placed if additional ballast is required.
Traditional and heretofore known plastic barricades have a functional weakness in that if a gust of wind rocks the barricade backward, the forward legs automatically fold to the rear and the barricade tumbles. A similar problem is encountered when the barricade is set up on a slope. Heavy sand bagging is often required to alleviate these problems.